Cytogenetic studies in a patient with acute granulocytic leukemia of seven and one-half years duration

During a 7 1/2-yr period we monitored a chromosomally aberrant cell line in a woman with acute granulocytic leukemia (AGL) whose disease followed a rather unusual course. Her initial remission induced with 6-mercaptopurine (6-MP) and prednisone was maintained for 52 mo with biweekly doses of methotrexate (MTX) given orally. Because signs of liver dysfunction occurred, maintenance therapy was stopped. After 15 mo without chemotherapy, she suffered her first relapse (5 yr 7 mo after the initial diagnosis). A second remission, again induced with 6-MP and prednisone, was maintained for 1 yr, after which a second relapse occurred. Another remission lasting for only 4 mo was followed by a relapse of the leukemic process which led to her death. Cytogenetic studies of marrow cells and peripheral blood at the time of her initial diagnosis showed abnormal stem lines with characteristic chromosome markers. A small percentage of malignant cells bearing these markers persisted in her marrow during the years of her prolonged remission. At the time of her first relapse, 75% of her marrow cells had the marker karyotype, and at the time of her death (7 1/2 yr after the leukemia was diagnosed) all analyzable marrow metaphases had the characteristic chromosome changes.